Electrically operated saddle type vehicle

ABSTRACT

An electrically operated saddle type vehicle includes a vehicle frame having at least one front wheel supported on a front wheel supporting member mounted adjacent to a front portion of the vehicle frame and at least one rear wheel supported on a rear wheel supporting member mounted adjacent to a rear portion of the vehicle frame. An electric motor is supported on the vehicle frame between the front wheel and the rear wheel and includes a front portion positioned adjacent to the front wheel. A transmission member is operatively connected to the electric motor and at least one of the front and rear wheels for providing propulsion for the vehicle. Wherein air is directed to contact the electric motor while the vehicle is in motion for cooling the electric motor during use.

This application is a divisional of application Ser. No. 08/180,768,filed on Jan. 10, 1994 now U.S. Pat. No. 5,501,292, which was aContinuation of Ser. No. 07/739,839 filed on Aug. 2, 1991, now abandonedthe entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a two-wheeled or three-wheeled electricallyoperated saddle type vehicle. More particularly, to a driving apparatusfor an electrically operated saddle type vehicle and to the suspensionof an electric motor on a body frame such that it is opposed to a frontwheel so that air may be introduced to the electric motor to cool theelectric motor.

2. Description of Background Art

An electrically operated saddle type vehicle carries an electric motorand a battery thereon and is driven by supplying power from the batteryto the electric motor. In such electrically operated saddle typevehicle, the electric motor and battery both have a certain weight. Inaddition, the battery has a large volume. Thus, mounting the electricmotor and the battery on a body frame is subject to positionalrestriction.

Conventionally, an electrically operated saddle type vehicle is knownwherein a hanger member is suspended on a body frame and a battery isplaced at a front portion of the hanger member. An electric motor isplaced at a rear portion of the hanger member. The electric motor isdisposed such that an output power shaft thereof may be located in acoaxial relationship with a pivot shaft, as disclosed, for example, inthe official gazette of Japanese Utility Model Laid-Open Application No.51-80848.

However, the electrically operated saddle type vehicle of the officialgazette of Japanese Utility Model Laid-Open Application No. 51-80848mentioned above has a problem that, since the battery is locatedforwardly of the electric motor, the cooling performance for theelectric motor is thereby deteriorated.

In addition, an electrically operated vehicle is advantageous in that anelectric motor is utilized to drive the driving wheel. Thus, the vehicledoes not discharge exhaust gas. Accordingly, the vehicle may be employedin a special environment such as indoors.

However, in a conventional electrically operated vehicle as described inJapanese Utility Model Laid-Open Application No. 51-80848, a high torqueis essential for an output of the electric motor and the electric motormust be energized with a high current. Consequently, there is a problemin that the heat generation of the electric motor is high and theelectric motor is liable to be thermally fatigued.

As a conventional electrically operated two-wheeled vehicle, a vehicleis known which is disclosed, for example, in the Official Gazettepublication of Japanese Utility Model Laid-Open Application No.51-80848. In the electrically operated two-wheeled vehicle, a drivingsprocket wheel is mounted on an output power shaft of an electric motorwhile a driven sprocket wheel is mounted on a rear wheel. A chain isstretched between the sprocket wheels to interconnect the electric motorand the rear wheel.

However, with the conventional electrically operated two-wheel vehicledescribed above, in order to change the speed of the vehicle, the speedof rotation of the electric motor must be controlled. There is a problemin that it is difficult to operate the electric motor always in a highefficiency. Thus, a savings in power consumption cannot be achieved.

The problem described above can be solved by assembling a transmissionmechanism in operative relationship relative to the electric motor andchanging the speed of the output of the electric motor by means of thetransmission mechanism. Since an assembly of the electric motor and thetransmission mechanism, power unit, is increased in size and also inweight, it is believed that the construction would be difficult.

In a motorcycle of the electric motor driven type, it is common practicethat an electric motor serving as a driving source is supported by meansof a body frame at a lower portion of the body frame, as described inJapanese Utility Model Laid Open Application No. 51-80848.

However, such a conventional vehicle as described above has a drawbackbecause the electric motor is located at a lower portion of the bodynear to the ground. The motor is liable to be adversely affected by dustor water from the ground.

SUMMARY AND OBJECTS OF THE INVENTION

The present invention has been made in view of the problem describedabove and provides and electrically operated saddle type vehicle whichcan achieve improvement in cooling performance of an electric motor.

An electrically operated saddle type vehicle of the present inventionincludes a front wheel which is supported on a front wheel supportingmember mounted at a front portion of a body frame while a rear wheel issupported on a rear wheel supporting member mounted at a rear portion ofthe body frame. An electric motor is suspended between a mountingportion of the front wheel supporting member and the rear wheelsupporting member on the body frame such that a front portion thereof isopposed to the front wheel. The electric motor is connected to at leastone of the front and rear wheels by way of a power transmittingmechanism.

In the electrically operated saddle type vehicle according to thepresent invention, since the electric motor is disposed such that thefront portion thereof is opposed to the front wheel, a driving wind cancollide directly with the electric motor to cool the electric motor andthe cooling performance of the electric motor can be improved.

It is an object of the present invention to provide a cooling apparatusfor effectively cooling an electric motor.

According to the present invention, a cooling apparatus for anelectrically operated vehicle includes a cooling water passagewayprovided for the electric motor, and a pump for supplying cooling waterto the cooling water passageway.

The cooling apparatus for an electrically operated vehicle of thepresent invention can effectively cool the electric motor since heat ofthe electric motor is absorbed by the cooling water supplied from thepump to the cooling water passageway.

The present invention provides a saving in power consumption. It is anobject of the present invention to provide a driving apparatus for anelectrically operated two-wheeled vehicle which is easy in layout andcan operate an electric motor in a high efficiency.

According to the present invention, a driving apparatus for anelectrically operated two-wheeled vehicle wherein output power of anelectric motor is changed in speed by a non-stage transmission. Thepower changed in speed by the non-stage transmission is transmitted to adriving wheel by way of a wrapping connector to drive the driving wheel.The electric motor and the non-stage transmission are assembledintegrally to each other and suspended at a lower portion of a bodyframe. The electric motor and the non-stage transmission are disposedsuch that a straight line interconnecting a rotary shaft of the electricmotor and an output power shaft of the non-stage transmission may extendsubstantially in parallel to the body frame as viewed in side elevation.

With the driving apparatus for an electrically operated two-wheeledvehicle according to the present invention, since the electric motor andthe non-stage transmission are assembled integrally to each other anddisposed at the lower portion of the body frame, the location of thecenter of gravity at a low position can be achieved. Further, since theelectric motor and the non-stage transmission are disposed such that thestraight line interconnecting the rotary shaft of the electric motor andthe output power shaft of the non-stage transmission may besubstantially in parallel to the body frame as viewed in the sideelevation, a dead space below the body frame can be utilized effectivelyand a layout can be easily achieved.

The driving apparatus for an electrically operated two-wheeled vehicleof the present invention provides a swing arm mounted for rocking motionaround a pivot shaft on the body frame by means of the pivot shaft. Thedriving wheel is supported on the swing arm adjacent to the output powershaft of the non-stage transmission. The pivot shaft is disposed in acoaxial relationship with the transmission. A driving wheel of thewrapping connector is securely mounted on the output power shaft of thenon-stage transmission. Variation in tensile force of an endlesstransmitting member of the wrapping connector can be reduced uponbounding or rebounding of the driving wheel.

Further, in the driving apparatus for an electrically operatedtwo-wheeled vehicle of the present invention, where the electric motorand the non-stage transmission are disposed such that the electric motoris located forwardly on the vehicle, the electric motor can beeffectively cooled.

It is an object of the present invention to provide an electricallyoperated vehicle which is not influenced by dust, rainwater or the likefrom the ground for providing an improvement in facility of maintenanceof the electric motor.

An electrically operated vehicle includes an electric motor serving as adriving source and an output power shaft connected to a driving wheeldisposed on the upper side and the lower side, respectively. Atransmission is interposed substantially at the center of the body framebetween the electric motor and the output power shaft. Further, abattery is disposed forwardly of the output power shaft and thetransmission. The electric motor is of the air cooling type having a fanbuild therein. Since the electric motor is located on the upper side ofthe output power shaft and the transmission and located at a positionspaced away from the ground and the lower side of the electric motor iscovered by the output power shaft and the transmission, dust, water orthe like is not able to directly enter into the electric motor.

In addition, the electric motor disposed above the body frame can beremoved or inserted readily from the side of the body independently ofthe output power shaft and the transmission. Improvement in maintenancecan be achieved.

The electric motor includes a cooling function. Even if the cooling unitis disposed at a location rearwardly of the battery where the coolingunit is not exposed very much to a driving wind, there is no trouble inthe functioning of the cooling unit.

Further scope of applicability of the present invention will becomeapparent from the detailed description given hereinafter. However, itshould be understood that the detailed description and specificexamples, while indicating preferred embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus are not limitativeof the present invention, and wherein:

FIG. 1 is a side elevational view of an electrically operated saddletype vehicle according to the present invention;

FIG. 2 is a sectional view of an essential portion of the electricmotor;

FIG. 3 is a side elevational view of a second embodiment of the presentinvention;

FIG. 4 is a front elevational sectional view thereof;

FIG. 5 is a side elevational view of a third embodiment of the presentinvention;

FIG. 6 is a perspective view of a principal portion thereof;

FIG. 7 is a side elevational view of a fourth embodiment of the presentinvention;

FIG. 8 is a side elevational view of a fifth embodiment of the presentinvention.

FIG. 9 is a side elevational view of an electrically operatedtwo-wheeled vehicle illustration a cooling apparatus attached thereto;

FIG. 10 is a sectional view of an essential portion:

FIG. 11 is a side elevational view of an electrically operatedtwo-wheeled vehicle showing a driving apparatus;

FIG. 12 is an enlarged side elevational view of an essential portion;

FIG. 13 is a sectional view of an essential portion;

FIG. 14 is a side elevational view of an electrically operatedtwo-wheeled vehicle according to another embodiment;

FIG. 15 is a sectional view of an essential portion;

FIG. 16 is a sectional view of an essential portion of a drivingapparatus for an electrically operated two-wheeled vehicle according toa further embodiment of the present invention.

FIG. 17 is a side elevational view of a motorcycle according to anotherembodiment of the present invention;

FIG. 18 is a plane view of the motorcycle illustrated in FIG. 17;

FIG. 19 is a side elevational view of a body frame as well as a powerapparatus and a battery carried on the body frame;

FIG. 20 is a left-hand side elevational sectional view of the powerapparatus shown in FIG. 19;

FIG. 21 is a right-hand side elevational sectional view of the powerapparatus shown in FIG. 19;

FIG. 22 is a sectional view of the power apparatus; and

FIG. 23 is a front elevational view of the body frame.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments of the present invention will be described with reference tothe drawings wherein FIGS. 1 and 2 show a first embodiment of anelectrically operated two-wheels vehicle, electrically operated saddletype vehicle. FIG. 1 is a side elevational view and FIG. 2 is asectional view of principal portions thereof.

Referring to FIG. 1, a body frame 11 includes a pair of left and rightmain frames 13, 13 which are mounted at front ends thereof on a headtube, mounting portion 12 and extend obliquely, rearwardly downwards. Across member, not shown, is provided between the main frames 13, 13. Afront wheel supporting member 14 is supported for steering operationwithin the head tube 12. A steering handle 15 is provided at an upperportion of the front fork 14 while a front wheel 16 is supported at alower portion of the front fork 14. In addition, a head lamp 17 and awind screen 18 are mounted at the front portion of the head tube 12.

A box 21 is positioned at upper portions of the main frames 13, 13 and aseat frame 22 extends rearwardly at an intermediate location below thebox 21. A pivot shaft, mounting portion 23 is provided at lower portionsof rear ends of the main frames 13, 13. A swing arm rear wheelsupporting member 24 is mounted for rocking motion on the pivot shaft 23and extends rearwardly. The box 21 is formed such that at least aportion thereof may be opened. A controller 25, for the control of anelectric motor, is disposed in the box 21. In addition, an articleaccommodating section, not shown, is defined in the box 21. The seatframe 22 includes a pair of left and right seat rails 22a, 22a havingfront ends connected to the main frames 13, 13. A pair of left and rightseat stays 22b, 22b having front ends connected to the main frames 13,13 are connected at rear ends thereof to each other in such a manner asto form a triangular frame as viewed in side elevation. A seat 26 ispositioned at an upper portion of the seat frame 22 while a pillion step27 is provided at an intermediate portion of the seat frame 22 by a stay28. A rear wheel 29, connected to a power unit 31, which will behereinafter described, is supported at a rear end of the swing arm 24. Acushion unit 30 is interposed between the swing arm 24 and the mainframes 13. Further, a speed change pedal 32 and a stand 33 areoperatively connected adjacent to a lower end of the body frame 11.

The power unit 31 and a battery frame 34 are suspended at lower portionsof the main frames 13, 13. The power unit 31 and battery frame 34 aresurrounded by a cover 35. The battery frame 34 has a substantiallycage-like configuration and is suspended at a lower portion of the powerunit 31. A plurality of batteries 68, 68, 68 wired in parallel or inseries to each other are carried on the battery frame 34. The batteries68 are connected to the aforementioned controller 25 and an electricmotor of the power unit 31. The cover 35 has a substantially L-shapedprofile as viewed in side elevational section and is mounted at frontand rear portions of an upper portion thereof on the main frames 13 andat front and rear portions of a lower portion thereof on the batteryframe 34. A wind introducing hole, not shown, is formed at a frontportion of the cover 35 in an opposing relationship to the power unit. Awind discharging hole 35a is formed at a lower rear portion of the cover35.

As shown in FIG. 2, the power unit 31 is constructed such that abrushless dc electric motor 36 and a transmission 37 are assembledrelative to each other as shown in FIG. 2. The electric motor 36includes a bottomed cylindrical motor case 38, opened at a left end andclosed at a right end thereof. The motor case 38 is secured to atransmission case 39 of the transmission 37. A rotary shaft 40 extendsthrough and is supported for rotation on the closed end of the motorcase 38. A stator housing 41, substantially in the form of a disk, ismounted at the open end of the motor case 38 to close the opening. Aleft end of the rotary shaft 40 is supported for rotation on the statorhousing 41. A permanent magnet 42 including a rotor is mounted at asubstantially central portion of the rotary shaft 40.

A fan 43 is mounted at a portion of the rotary shaft 40 to the right ofthe permanent magnet 42 adjacent the closed end of the motor case 38. Amagnet 44 having a plurality of magnetic poles for the detection ofrotation is securely mounted at an end portion of the rotary shaft 40which extends outwardly of the stator housing 41. The rotary shaft 40extends at a right end thereof into the transmission case 39. A drivegear 52 is mounted at the right end of the rotary shaft 40 and isconnected to a clutch, which will be hereinafter described. A pluralityof coils 45 constituting a stator are mounted at a cylindrical portion41a on one face of the stator housing 41 which extends into the motorcase 38. A heat sink 46 having fins 46a thereon is formed integrally onthe other face of the stator housing 41. A rotation detector 47 having aHall effect element is provided in an opposing relationship to themagnet 44 of the rotary shaft 40. Though not shown clearly in thedrawings, an FET, field effect transistor, is connected to thecontroller 25 and the coils 45 described hereinabove. The FET includes amotor driving circuit provided on the heat sink 46. In addition, therotation detector 47 is connected to the controller.

A cover 48 is mounted on the stator housing 41 and covers theaforementioned FET. Vent holes 49a, 49b and 49c are formed in the cover48, motor housing 41 and motor case 38, respectively. The inside of themotor case 38 is ventilated as indicated by arrow marks in FIG. 2 byrotation of the fan 43 so that the coils 45 are cooled.

The electric motor 36, described hereinabove, is disclosed in detail inJapanese Patent Application No. 1-181496 or Japanese Utility ModelApplication No. 2-51139 which have been previously filed by the presentinventors and incorporated herein by reference. Thus, a detaileddescription thereof is not provided herewith.

The transmission 37 includes a clutch chamber 39a and a transmissionchamber 39b which are defined in the transmission case 39. A multipledisk type clutch 50 is disposed in the clutch chamber 39a while atransmission mechanism 51 of the parallel gear type is disposed in thetransmission chamber 39b. The clutch 50 includes a driven gear 53 whichis held in meshing engagement with a drive gear 52 of the rotary shaft40 of the electric motor 36. A clutch outer member 54 is provided whilea clutch inner member 55 is mounted on a main shaft of the transmissionmechanism 51. Pressure plates 56 supported on the clutch outer member 54and pressure plates 57 supported on the clutch inner member 55 areengaged for alternate frictional contact with each other in an axialdirection such that the pressure plates 56 and 57 are frictionallycontacted with each other by axial movement, movement to the right inFIG. 2, of a pressing member 58 connected to a clutch lever, not shown,to transmit power.

The transmission mechanism 51 includes a main shaft 59 and a countershaft 60 which are disposed in parallel to each other in thetransmission chamber 39b such that a right end of the main shaft 59extends into the clutch chamber 39a and the clutch inner member 55 ismounted at the right end of the main shaft 59 as described hereinabove.A left end of the counter shaft 60 extends outwardly of the transmissioncase 39 and a sprocket wheel 61 is provided at the left end of thecounter shaft 60. Speed change gears 61a, 61b, 61e and 61f and a shifter69 having speed change gears 61c and 61d formed thereon are providedcorresponding to a number of speeds on the main shaft 59. Speed changegears 62a, 62c, 62d and 62f, a shifter 63 having a speed change gear 62bformed thereon and another shifter 64 having a speed change gear 62eformed thereon are provided on the counter shaft 60. The shifters 63, 64and 69 are held in engagement with shift forks, not shown, which aremoved in response to a treadling operation of the speed change pedal 32.In the transmission mechanism 51, the shifters 64, 65 and 69 areselectively moved in an axial direction by a treadling operation of thespeed change pedal 32 to effect speed changing. Though not shown clearlyin FIG. 2, a chain power transmitting mechanism 66 is stretched betweenthe sprocket wheel 61 and another sprocket wheel provided on an axle ofthe rear wheel 29. A vehicle speed detector 67 is connected to theaforementioned controller 25.

Subsequently, operation of the present embodiment will be described. Inthe electrically operated two-wheeled vehicle, an operational angle ofan accelerator grip of the steering handle 15 is detected by anaccelerator sensor not shown. The speed of rotation of the rotary shaft40 of the electric motor 36 is detected by the rotation detector 47. Thespeed of the vehicle is detected by the vehicle speed detector 67. Ashift position of the transmission mechanism 51 and a condition of theclutch 50 are detected by respective sensors. Thereafter, in accordancewith the detection signals, the controller 25 determines the conditionsof the vehicle and energizes the electric motor 36 to cause the rearwheel 29 to be driven by the electric motor 36 to drive the vehicle. Thecontroller 25 operates the electric motor 36 in the highest efficiency,for example, as described also in the precedent Japanese application toachieve a saving in the power consumption.

Meanwhile, in the electrically driven two-wheeled vehicle, the electricmotor 36 is disposed at a forwardmost position in the cover 35 such thata front portion thereof is opposed to the air introducing hole of thecover 35 so that a driving wind collides with the electric motor 36 byway of the air introducing hole of the cover 35. Consequently, theelectric motor 36 can radiate, upon driving, the heat generated from thecoils 45 or the FET by energization. Thus, a high cooling performancecan be obtained. More particularly, because the fan 43 is rotatedtogether with the rotary shaft 40 of the electric motor 36 to ventilatethe inside of the motor case 38, forced air cools the inside of themotor case 38. The temperature rise of the coils 45 and so forth can beprevented.

Meanwhile, in the present electrically operated two-wheeled vehicle, thepower unit 31 is suspended below the main frames 13. The batteries 68are suspended below the power unit 31, consequently, the power unit 31and the batteries 68 having a great weight can be disposed on a lowerside with respect to the body frame 11 to achieve a location of thecenter of gravity at a low position and obtain a high degree of drivingstability.

FIGS. 3 and 4 show a second embodiment of the present invention. In thesecond embodiment and several embodiments which will be hereinafterdescribed, like reference numerals are applied to like portions to thoseof the first embodiment described above and a description thereof willbe omitted herein.

In the second embodiment, a battery case 70 having batteries 68accommodated therein is mounted in a box 21. The box 21 is supported ata front portion thereof for pivotal motion. The battery case 70 ismounted, by way of rubber members 72, 72, between brackets 71, 71mounted on inner faces of main frames 13, 13. The battery case 70 isopened at an upper portion thereof. A lid 70a is provided for openingand closing movement at the upper portion.

In the second embodiment, a sprocket wheel 61 is mounted directly on arotary shaft 40 of an electric motor 36. A chain 66 is stretched betweenthe sprocket wheel 61 and another sprocket wheel on a rear wheel 29. Thebatteries 68 are carried in the box 21 and are spaced apart a largedistance. The layout is easy and a large number of batteries 68 can becarried in the box 21.

The electrically operated two-wheeled vehicle includes the sprocketwheel 61 which is mounted directly on the rotary shaft 40 of theelectric motor 36. Energization of the electric motor 36 is controlledto effect speed changing equivalent to the transmission 37. Further,miniaturization and reduction in weight can be achieved.

FIGS. 5 and 6 show a third embodiment of the present invention. A case70 may be opened at an upper portion thereof between left and right mainframes 13', 13'. Batteries 68 are carried in the case 70'.

Because the batteries 68 are positioned between the main frames 13', 13'which provide a dead space therebetween, no adverse influence occurs onthe layout of any other mechanism. Further, miniaturization can beachieved. Also, designing or the like is facilitated.

A fourth embodiment of the present invention is shown in FIG. 7. A motorcase 38' of an electric motor 36 is used as a main frame. A frontportion of the motor case 38' is mounted on a head pipe 12 while a swingarm 24 is supported at a rear portion of the motor case 38'. Though notshown clearly in FIG. 7, the electric motor 36 includes an airintroducing hole formed in the motor case 38'. A rotor, a stator and soforth are assembled in the motor case 38' similarly to the firstembodiment described hereinabove. Meanwhile, a bevel gear mechanism, asprocket wheel and so forth are provided in the motor case 38' and arotary shaft is connected to the sprocket wheel by way of the bevel gearmechanism. Batteries 68' are suspended on a lower side of the motor case38'.

In the fourth embodiment, since the motor case 38' of the electric motor36 is used as the main frame, there is no necessity of assuring thelocation for the electric motor 36. Further, miniaturization can beachieved.

A fifth embodiment of the present invention is illustrated in FIG. 8.Batteries 68", 68" are disposed above and below an electric motor 36".The batteries 68", 68" are individually wired in parallel or in seriesto each other.

The batteries 68", 68" are disposed separately from each other. Thedegree of freedom in layout of the batteries 68", 68" is high and thelayout of any other mechanism is not restricted. Designing isfacilitated.

While an electrically operated two-wheeled vehicle is illustrated ineach of the embodiments described hereinabove, the present invention canalso be applied to a three-wheeled vehicle.

As described hereinabove, an electrically operated saddle type vehicleaccording to the present invention includes an electric motor which isopposed to a front wheel so that a driving wind may collide directlywith the electric motor. The electric motor can be cooled with a drivingwind and a high cooling performance can be obtained.

FIGS. 9 and 10 illustrate a cooling apparatus for an electricallyoperated vehicle according to another embodiment of the presentinvention. Referring to FIG. 9, a body frame 111 includes a pair of leftand right main frames 112, 112 which are mounted at front ends thereofon a head tube 113 and extend obliquely rearwardly and a cross member,not shown, is provided between the main frames 112, 112. A front wheel114 is supported on the head tube 113 by way of a front fork 115 forsteering operation by a steering handle 116. A head lamp 117, a meterbox 118, and a wind screen 119 are operatively connected to the headtube 113.

A box 120 is positioned at an upper portion of the body frame 111. Aseat frame 121 extends rearwardly from below the box 120 while a swingarm 122 is supported for rocking motion at a rear portion of the bodyframe 111 by a pivot shaft 123. Though not shown, a controller, which isconnected to an electric motor which will be hereinafter described, anda battery and so forth, controls the electric motor and is disposed inthe box 120. An article accommodating section for accommodating a tooland so forth therein is defined in the box 120. A seat 126 is placed atan upper portion of the seat frame 121. A rear wheel 124 is supported ata rear end of the swing arm 122. The rear wheel 124 has a drivensprocket wheel 125 mounted at a hub or the like thereof and is connectedto a power unit, which will be hereinafter described, by way of a chain138 so that power may be transmitted thereto. A cushion unit 128 and apillion step 130 are operatively positioned relative to the main frames112, 112 and the rear of the vehicle.

A power unit 127 and a battery frame 131 are suspended on the main frame111. Further, a cover member 132 is positioned adjacent to the powerunit 127. The cover member 132 has a substantially L-shaped profile asviewed in side elevation and is mounted at a front upper portion thereofon the main frame 111 and at lower front and rear portions thereof onthe battery frame 131. An opening 132a is formed in the cover member 132in an opposing relationship to a radiator which will be hereinafterdescribed. A large number of air introducing holes 132b are formed inthe cover member 132 around the opening 132a so as to allow ventilation.The battery frame 131 is formed from pipe-shaped members assembled intoa substantially cage-like configuration and is mounted at two forwardlyand rearwardly spaced points on the power unit 127 and at a lowerportion of the body frame 111 rearwardly of the power unit 127 and at alower portion of the body frame 111 rearwardly of the power unit 127. Aplurality of batteries 133 are carried on the battery frame 131. Thebatteries 133 are connected in parallel and in series to each other andconnected to the controller and an electric motor of the power unit 127.

The power unit 127 is constructed such that, as shown also in FIG. 10, adc electric motor 134 and a transmission 135 of the parallel gear typeare assembled forwardly and rearwardly into a single body. A radiator136 is mounted at a front portion of the electric motor 134 while awater pump 137 is mounted at a left side portion of the electric motor134. The radiator 136 is in communication with a water jacket,hereinafter described, of the electric motor 134 by way of a hose 146and also with the water pump 137 by way of a pipe 145 and cools coolingwater admitted therein from the water pump 137. It is to be noted thatconstruction of the radiator 136 is well known and description thereofis omitted herein.

The electric motor 134 is mounted in a bottom cylindrical motor case 139including an accommodating portion 139b which is open to the left, asillustrated in FIG. 10. The bottom portion of the motor case 139 ismounted on a transmission case 140 of a transmission 135. A plurality ofvent holes 139c are formed in the bottom portion of the motor case 139.A water jacket cooling water passageway 139a having a substantiallyannular section is formed in the motor case 139 in a coaxialrelationship to the accommodating portion 139b. The vent holes 139c areformed in an opposing relationship to a fan which will be hereinafterdescribed so as to allow ventilation therethrough. When the fan rotates,a cooling air passes through the vent holes 139c. The water jacket 139ais opened annularly to the same side as the opening of the accommodatingportion 139b. The opening thereof is closed by a stator holding member141 which will be hereinafter described. The water jacket 139a iscommunicated with the radiator 136 from an inlet port formed in thestator holding member 141 so that cooling water is supplied thereto.Further, the water jacket 139a is similarly in communication with thewater pump 137 from an outlet port formed in the stator holding member141 so that cooling water is discharged therefrom.

The stator holding member 141 is mounted at the opening end of the motorcase 139. A rotary shaft 142 is supported for rotation inside the motorcase 139 between the stator holding member 141 and the bottom portion.The stator holding member 141 has a plurality of holding pieces 140bintegrally formed in an equidistantly spaced relationship in acircumferential direction projecting on an inner face of a lid portion140a having a substantially disk-like configuration. The lid portion140a closes the opening of the accommodating portion 139b and theopening of the water jacket 139a of the motor case 139. Coils 143include a stator mounted on the individual holding pieces 140b. Aplurality of vent holes 141a are formed in the lid portion 140a on thecenter side with respect to the holding pieces 149b. An inlet port 144iand an outlet portion 144o are formed at locations on the lid portion140a corresponding to the opening of the water jacket 139a such thatthey are opened to the water jacket 139a. The vent holes 141a are formedin an opposing relationship to the coils 143 so as to allow ventilation.When the fan rotates, a cooling air passes through the vent holes 141a.The inlet portion 144i is connected to the hose 146 so that it iscommunicated with the radiator 136 by way of the hose 146 while theoutlet port 144o is connected to a pipe 181 so that it is incommunication with the radiator 136 by way of the pipe 181.

The rotary shaft 142 extends at the opposite ends thereof leftwardly andrightwardly through the stator holding member 141 and the bottom portionof the motor case 139. The left end thereof is connected to the waterpump 137 while a driving gear 147, which is held in meshing engagementwith a driven gear of the transmission 135 in the transmission case 140,is mounted at the right end of the rotary shaft 142. A well known magnet148 constituting a rotor in the coils 143 is mounted on the rotary shaft142 in the motor case 139. A fan 149 is securely mounted on the rotaryshaft 142 in the neighborhood of the bottom portion of the motor case139. The fan 149 is rotated integrally with the rotary shaft 142 tointroduce a cooling air through the vent holes 141a. The cooling airwhich has cooled the coils 143 and so forth is discharged through thevent holes 139c.

A rotation sensor 150 includes a magnet 150a mounted on the rotary shaft142 and a magnetic sensitive element 150b such as an MR element disposedin an opposing relationship to the magnet 150a. As is well known, themagnet 150a has a plurality of magnetic poles disposed in a direction ofrotation of the rotary shaft 142 and the magnetic responsive element 150operates in response to magnetism. The magnetic responsive element 150bof the rotation sensor 150 is connected to the controller and outputs asignal representative of a speed of rotation of the rotary shaft 142.

The water pump 137 is provided within a pump case 151 which is mountedon an outer edge portion of an outer periphery of the stator holdingmember 141 by means of a bracket 154 such that a central portion thereofis spaced from the outer face of the stator holding member 141. Aspacing 153 is defined between the pump case 151 and the stator holdingmember 141. The spacing 153 is in communication with the atmospheric airby way of a hole or the like, not shown, formed in the bracket 154. Theaforementioned vent holes 141a are opened to the spacing 153.

The pump case 151 has a pump chamber 155, a water sucking passageway156, a water sending passageway 157 and a supporting hole 158 definedtherein. A rotary shaft 152 extends in the supporting hole 158 in acoaxial relationship to the rotary shaft 142 of the electric motor 134.The rotary shaft 152 is connected at a right end thereof to the rotaryshaft 142 of the electric motor 134 and extends at a left end thereofinto the pump chamber 155. A blade 159 is mounted at the right end ofthe rotary shaft 152. The water sucking passageway 156 extends in aradial direction and is opened at an inner end thereof to a centralportion of the pump chamber 155 while it is in communication at an outerend thereof with the outlet port 144o of the water jacket 139a by way ofthe pipe 181 mentioned hereinabove. Similarly, the water sendingpassageway 157 extends in a radial direction and is in communication atan inner end thereof with an outer peripheral portion of the pumpchamber 155 while it is communicated at an outer end thereof with theradiator by way of the pipe 145. The water pump 137 is driven by theelectric motor 134 so that the blade 159 is rotated to send out coolingwater from within the water jacket 139a of the electric motor to theradiator 136.

The transmission 135 includes a clutch chamber 161 and a transmissionchamber 162 which are defined in the transmission case 140. A multipledisk type clutch 163 is disposed in the clutch chamber 161. Atransmission mechanism 164 of the parallel gear type is disposed in thetransmission chamber 162. The clutch 163 includes a driven gear 165which is held in meshing engagement with the aforementioned driving gear147 which is provided on a clutch outer member 166 while a clutch innermember 167 is mounted on a main shaft of the transmission mechanism 164.As is well know, the clutch plates 168 and 169 are provided on theclutch outer member 166 and the clutch inner member 167, respectively.The clutch plates 168 and 169 are engaged for frictional contact witheach other. In the clutch 163, a pressing member 170 is moved in anaxial direction by operation of a clutch lever, not shown, to press theclutch plates 168 and 169. Power is transmitted through frictionalcontact between the clutch plates 168 and 169.

The transmission mechanism 164 includes a main shaft 171 and a countershaft 172 which are disposed in parallel to each other in thetransmission chamber 162 such that a right end of the main shaft 171extends into the clutch chamber 161. The clutch inner member 167described hereinabove is mounted at the right end of the main shaft 171while a left end of the counter shaft 172 extends outwardly of thetransmission case 140. A driving sprocket wheel 173 is securely providedat the left end of the counter shaft 172. Speed change gears 174a, 174b,174e and 174f and a shifter 175 having speed change gears 174c and 174dformed thereon are provided corresponding to shift positions on the mainshaft 171. Speed change gears 176a, 176d and 176f, a shifter 177 havinga speed change gear 176b formed thereon and another shifter 178 having aspeed change gear 176e formed thereon are provided on the counter shaft172. The shifters 175, 177 and 178 are held in engagement with shiftforks, not shown, which are connected to a speed change pedal, notshown, so that they are selectively moved in an axial direction by atreadling operation of the speed change pedal into a connected conditionto a speed change gear to make integral rotation. A vehicle speeddetector 179 is connected to the aforementioned controller and outputs asignal representative of a speed of the vehicle.

The chain 138 is stretched between the driving sprocket wheel 173 andthe driven sprocket wheel 125 of the aforementioned rear wheel 124 sothat the driving sprocket wheel 173 and the driven sprocket wheel 125are interconnected for power transmission by way of the chain 138.

In the electrically operated two-wheeled vehicle of the presentembodiment, the electric motor 134 is energized and power outputted fromthe electric motor 134 is changed in speed by the transmission 135.Power is transmitted from the transmission 135 to the rear wheel 124 todrive the electrically operated two-wheeled vehicle. Here, duringenergization of the electric motor 134. The water pump 137 circulatescooling water so that cooling water in the water jacket 139a flows intoand is cooled by the radiator 136. Thereafter, the cooling water cooledby the radiator 136 flows into the water jacket 139a to cool the motorcase 139. Further, in this instance, the fan 149 is rotated integrallywith the rotary shaft 142 so that a cooling air flows through the ventholes 141a into the motor case 139. The cooling air passes through themotor case 139 and is discharged through the vent holes 139c to cool thecoils 143 and so forth. Accordingly, even when a comparatively highcurrent is supplied to the coils 143 to generate a great amount of heat,the electric motor 134 can be cooled effectively and a temperature riseof the electric motor 134 can be restricted.

Further, in the electric motor 134 of the present embodiment, the waterjacket 139a is opened to the same side as the accommodating portion139b. Further, the water jacket 139a is formed in such a shape that ithas a substantially equal section in the opening direction. The shapefacilitates removal from a die. The opening of the water jacket 139a isclosed watertight by the stator holding member 141. Accordingly, themotor case 139 can be shaped readily by casting or the like.

As described so far, according to a cooling apparatus for anelectrically operated vehicle of the present invention, an effect can beobtained in that an electric motor can be cooled effectively and atemperature rise of the electric motor can be restricted.

FIGS. 11 to 13 illustrate a driving apparatus for an electricallyoperated two-wheeled vehicle according to an embodiment of the presentinvention. FIG. 11 is a side elevational view of the entire electricallyoperated two-wheeled vehicle. FIG. 12 is an enlarged side elevationalview of an essential portion. FIG. 13 is a sectional view of theessential portion illustrated in FIG. 12.

Referring to FIG. 11, body frame 211 includes a pair of left and rightmain frames 212, 212 mounted at front ends thereof on a head tube 213.The main frames 212, 212 are provided to extend obliquely rearwardlyfrom the head tube 213. A cross member, not shown, is provided betweenthe main frames 212, 212. A front wheel 214 is supported on the headtube 213 by way of a front fork 215 for permitting steering operation bymeans of a steering handle 216. A head lamp 217, a meter box 218, and awind screen 219 are operatively connected to the head tube 213.

A box 220 is placed at an upper portion of the body frame 211. A seatframe 221 extends rearwardly below the box 220 while a pivot shaft 222is provided at rear portions of the main frames 212, 212. Though notshown, a controller is disposed in the box 220 and an articleaccommodating section for accommodating a tool and so forth therein isdefined in the box 220. The controller is connected to an electricmotor, which will be hereinafter described, a battery and so forth andcontrols the electric motor. A seat 223 is placed on the seat frame 221.A swing arm 224 is supported for rocking motion on the pivot shaft 222.It is to be noted that, while the controller in the present embodimentcontrols the electric motor so as to operate in a high efficiency. Acontrol system is disclosed in detail in Japanese Patent Application No.1-181496 which was filed prior to the present invention. Thus, a fulldescription is not presented herewith.

The swing arm 224 is mounted at a front end thereof for pivotal motionon the pivot shaft 222. A rear wheel, driving wheel, 225 is supported ata rear end of the swing arm 224. Though not shown in FIG. 11, the swingarm 224 has a substantially ladder-like configuration in plan andsupports the rear wheel 225 in a bilateral fashion thereon, asillustrated in FIGS. 15 and 16. The rear wheel 225 is connected to apower unit which will be hereinafter described by way of a wrappingconnector 276, as illustrated in FIGS. 15 and 16, such that power may betransmitted to the rear wheel 225. The wrapping connector 276 includes adriven sprocket wheel 274 mounted on a hub or the like of the rear wheel225. A chain, endless transmitting members, 275 is stretched between thedriven sprocket wheel and a driving sprocket wheel of the power unit totransmit power. A cushion unit 226, a progressive link mechanism 227 anda pillion step 228 are operatively mounted to the rear of the vehicle.

A power unit 229 is suspended at a lower portion of the main frame 211.A battery 230 is carried below the power unit 229 by means of a batteryframe 280. A cover member 231 which covers a front portion and lowerportion of the power unit 229 and the battery 230 is hung on the mainframe 211. The cover member 231 has a substantially L-shaped profile asviewed in side elevation and is mounted at a front upper end thereof onthe main frame 211 and at a rear lower end thereof on the battery frame280. A large number of air introducing holes 281 are formed in a frontface of the cover member 231 in an opposing relationship to the powerunit 229 so that a driving wind may collide with the power unit 229 byway of the wind introducing holes 281. The battery frame 280 has asubstantially cage-like configuration and is suspended at a lowerportion of the power unit 229. A plurality of batteries 230, connectedin parallel or in series to each other, are placed on the battery frame280. The batteries 230 are connected to the controller and an electricmotor of the power unit 229.

The power unit 229 is constructed such that, as shown in FIG. 13, ahousing 233 is mounted at front and rear portions thereof on the mainframe 211 and an electric motor 234 is assembled in a recessed portion233a formed on the front right side of the housing 233. A non-stagetransmission 235 of the belt type is assembled in another recessedportion 233b formed on the front left side of the housing 233. Areducing gear mechanism 236 is assembled in a further recessed portion233c formed on the rear left side of the housing 233. The electricmotors 234, non-stage transmission 235 and reducing gear mechanism 236are formed in an integral relationship with each other. Referring toFIG. 12, the power unit 229 is mounted such that a straight lineinterconnecting a rotary shaft of the electric motor 234 and an outputpower shaft of the reducing gear mechanism extend substantially inparallel to the main frame 211 in side elevation, that is, the line maybe inclined rearwardly downwards.

The electric motor 234 includes a permanent magnet 238 constituting arotor mounted on a rotary shaft 237 which extends through a bottomportion of the recessed portion 233a into the recessed portion 233bwhile coils 240 constituting a stator are mounted on a stator member 239which closes an opening of the recessed portion 233a. The rotary shaft237 is supported for rotation on the bottom portion of the recessedportion 233a and the stator member 239. A driving pulley which will behereinafter described is mounted at a left end of the rotary shaft 237in the recessed portion 233b. A fan 244 is mounted on the rotary shaft237 adjacent to the bottom portion of the recessed portion 233a. Amagnet 241 having a plurality of magnetic poles for the detection ofrotation is securely mounted at a right end of the rotary shaft 237. Thefan 244 is located in an opposing relationship to a vent hole 245 formedin the recessed portion 233a and is rotated together with the rotaryshaft 237 to direct air from the recessed portion 233a toward therecessed portion 233b. The magnet 241 is provided in an opposingrelationship to a magnetic sensitive element 242 such as an MR elementprovided on the stator member 239 to provide a rotation sensor 243. Therotation sensor 243 detects rotation of the rotary shaft 237 and outputsa detection signal to the controller.

A cylindrical portion 239a holding the aforementioned coils 240 thereonis formed on an inner face of the stator member 239 on the recessedportion 233a side. A heat sink 239b for the radiation of heat is formedon an outer face of the stator member 239. Vent holes 239c for theventilation of a cooling air are formed at locations on the statormember 239 substantially the same as fins of the heat sink 239b. Aplurality of switching elements 246 such as FETs providing a drivingcircuit for the electric motor 234 are mounted on the heat sink 239b.The switching elements 246 are connected to the aforementionedcontroller together with the coil 240. The switching elements 246energize the coils 240 with a pulse current of a duty factorcorresponding to a PWM signal inputted from the controller.

A cover 247 is mounted on the outer face of the stator member 239 andcovers the heat sink 239. A hole 247a for the admission of a cooling airis formed in the cover 247. While detailed description is omittedherein, a cooling air is admitted through the hole 247a by rotation ofthe aforementioned fan 244. The cooling wind flows through the ventholes 239c, 245 and so forth to cool the electric motor 234 and thenon-stage transmission 235.

The non-stage transmission 235 includes a belt 250 stretched between adriving pulley 248 and a driven pulley 249. The driving pulley 248 isprovided on the rotary shaft 237 of the electric motor 234. The drivenpulley 249 is provided on an input shaft 251 of the reducing gearmechanism 236. The driving pulley 248 has a fixed face 252 mounted onthe rotary shaft 237 and a movable face 253 supported for axial movementon the rotary shaft 237. The movable face 253 is driven by a governormechanism 255 having a weight 254 thereon to move in an axial direction.In the driving pulley 248, the weight 254 is moved in a diametricaldirection by a centrifugal force in response to the speed of rotation ofthe rotary shaft 237 so that the wrapping diameter of the belt 250 isvaried.

The driven pulley 249 is provided on a sleeve 256 fitted for rotation onan outer periphery of the input shaft 251 and is connected to the inputshaft 251 by way of a parallel arrangement of a first centrifugal clutch257 and a second centrifugal clutch 258. The driven pulley 249 has afixed face 259 mounted on a right end of the sleeve 256. A movable face260 supported for axial movement on the sleeve 256 and a spring, notshown, for urging the movable face 260 toward the fixed face 259 side.The movable face 260 is moved in an axial direction in response to avariation in the wrapping diameter of the driving pulley 248 so that thebelt wrapping diameter is varied.

The first centrifugal clutch 257 includes a clutch outer member 262mounted at a left end of the sleeve 256 while a clutch inner member 263is provided on a clutch outer member 264 of the second centrifugalclutch 258 so that the first centrifugal clutch 257 is engaged ordisengaged in response to a speed of rotation of the clutch outer member264 of the second centrifugal clutch 258. The second centrifugal clutch258 includes the clutch outer member 264 secured to the input shaft 251while a clutch inner member 265 is provided on the clutch outer member262 of the first centrifugal clutch 257 so that the second centrifugalclutch 258 is engaged or disengaged in response to a speed of rotationof the first centrifugal clutch 257.

The reducing gear mechanism 236 includes the input shaft 251 extendingthrough a lid member 266 which closes an opening of the recessed portion233c and is supported for rotation on the lid member 266 and a bottomportion of the recessed portion 233c. An intermediate shaft 267 and anoutput power shaft 268 are supported on the bottom portion of therecessed portion 233c and the lid member 266. A gear 269 is securelymounted on the input shaft 251 and large and small gears 270 and 271 aremounted on the intermediate shaft 267 while a further gear 272 ismounted on the output power shaft 268. The gear 269 is held in meshingengagement with the gear 270 while the gear 271 is held in meshingengagement with the gear 272. The output power shaft 268 extendsrightwardly through and from the housing 233. A driving sprocket wheel273 is mounted on an outwardly extending end of the output power shaft268. As described hereinabove, the chain is stretched between thedriving sprocket wheel 273 and the driven sprocket wheel of the rearwheel 225 so that the driving sprocket wheel 273 is connected to therear wheel 225 so that power may be transmitted to the latter. Thereducing gear mechanism 236 reduces the speed of output power of theelectric motor 234 transmitted thereto by way of the non-stagetransmission 235 and transmits the power of the reduced speed to thewrapping connector 276, that is, to the rear wheel 225.

In the driving apparatus for an electrically operated two-wheeledvehicle, the electric motor 234 is energized with a pulse current of aduty factor corresponding to an amount of operation of an acceleratorgrip or the like. Power outputted from the electric motor 234 is changedin speed by the non-stage transmission 235 and transmitted to the rearwheel 225 by way of the reducing gear mechanism 236 and the wrappingconnector 276. Here, the non-stage transmission 235 changes the speed inresponse to a speed of rotation of the rotary shaft 237 of the electricmotor 234 to cause the electric motor 234 to operate in a highefficiency. Accordingly, saving of the power consumption can beachieved. It is to be noted that the construction and control for theachievement of the operation of the electric motor 234 in a highefficiency is disclosed in Japanese Patent Application No. 1-181496 andJapanese Utility Model Application No. 2-51139 filed prior to thepresent application and incorporated herein by reference.

Meanwhile, in the driving apparatus, the electric motor 234, non-stagetransmission 235 and reducing gear mechanism 236 are assembledintegrally to each other as the power unit 229. The power unit 229 iscarried at a lower portion of the body frame 211 to form a straight lineinterconnecting the rotary shaft 237 of the electric motor 234. Theoutput power shaft 268 of the reducing gear mechanism 236 may bepositioned substantially in parallel to the main frames 212 as viewed inside elevation. Accordingly, even the power unit 229 having a large sizecan be disposed effectively making use of a dead spacing below the mainframe 211 and without occupying a large spacing. In addition, the layoutof the mechanism is facilitated. Particularly since the power unit 229of the present driving apparatus is carried with the electric motor 234positioned forwardly, a driving air can collide with the electric motor234 to effectively cool the electric motor 234.

Further, in the present electrically operated two-wheeled vehicle, thepower unit 229 having a great weight is disposed at a lower portion ofthe main frame 211 while the batteries 230, which are also a heavyweight, are disposed below the power unit 229. Accordingly, a locationof the center of gravity at a lower position can be achieved and a highdegree of driving stability can be obtained.

A driving apparatus for an electrically operated two-wheeled vehicleaccording to another embodiment of the present invention is shown inFIGS. 14 and 15. FIG. 14 is a side elevational view of a two-wheeledvehicle. FIG. 15 is a sectional view of an essential portion.

It is to be noted that, in the description of the present embodiment anda further embodiment which will be hereinafter described, like referencenumerals are applied to like portions to those of the embodimentdescribed above and description thereof will be omitted herein.

As shown in FIG. 15, in the present embodiment, a power unit 229includes an electric motor 234 and a non-stage transmission 235. Thepower unit 229 is connected to a pivot shaft 222 extending for rotationthrough a rear portion of a housing 233 such that the rear portion ofthe housing 233 is supported on the pivot shaft 233. An output powershaft 268 is formed from a cylindrical member fitted for rotation on anouter periphery of the pivot shaft 222 and coaxial with the pivot shaft222. The output power shaft 268 extends at a right end thereof to theright from the housing 233. A driven pulley 249 of the non-stagetransmission 235 is provided on the output power shaft 268 in thehousing 233 by way of a sleeve 256 while a driving sprocket wheel 273 ismounted at the right end of the output power shaft 268' which extendsoutwardly from the housing 233. Similarly, as in the embodimentdescribed above, the driven pulley 249 is connected to the output powershaft 268' by way of a first centrifugal clutch 257' and a secondcentrifugal clutch 258'.

Also in the present embodiment, the power unit 229 is carried such thatthe electric motor 234 is located forwardly and a straight lineinterconnecting a rotary shaft 237 of the electric motor 234 and theoutput power shaft 268' may be substantially horizontal as viewed inside elevation. In other words, substantially in parallel to the mainframes 212 and the power unit 229. Batteries 230 are disposed below thebody frame 211. Accordingly, the layout of the power unit 229 is easyand the electric motor 234 can be cooled effectively. In addition, thelocation of the center of gravity at a low position can be achieved.

In the present embodiment, the driving sprocket wheel 273' is securelymounted on the output power shaft 268' coaxial with the pivot shaft 222.A chain 275 is stretched between the driving sprocket wheel 273' and adriven sprocket wheel 274 of a rear wheel 225. Accordingly, even whenbounding or rebounding takes place with the rear wheel 225, the distancebetween the driving sprocket wheel 273' and the driven sprocket wheel274 is not varied. Variation in tensile force of the chain 275 can beprevented.

FIG. 16 shows a further embodiment of the present invention. A pivotshaft 222" includes two shafts 222a and 222b and an output power shaft268" of a power unit 229 is disposed between the shafts 222a and 222b.The pivot shaft 222" including the shafts 222a and 222b are disposed ina coaxial relationship with each other. Left and right front portions ofa swing arm 224 are supported on a main frame 211 by means of the shafts222a and 222b. The power unit 229 including the output power shaft 268is supported on a housing 233 in a coaxial relationship with the shafts222a and 222b of the pivot shaft 222" between the shafts 222a and 222b.A driving sprocket wheel 273" is mounted at a right end portion of theoutput power shaft 268" which projects from the housing 233. It is to benoted that the remaining construction is similar to the embodiment shownin FIGS. 14 and 15.

Also with the embodiment illustrated in FIG. 16, the layout is easy andsimilar to the embodiments described hereinabove. Cooling of theelectric motor 234 can be performed effectively with a driving wind.Further, the location of the center of gravity at a low position of thevehicle body can be achieved. Variations in tensile force of the chain275 upon bounding or rebounding of the rear wheel 225 can be prevented.

As described so far, according to a driving apparatus for anelectrically operated two-wheeled vehicle according to the presentinvention, since an electric motor and a non-stage transmission areassembled integrally with each other as a power unit and the power unitis carried at a lower portion of a body frame such that a straight lineinterconnecting a rotary shaft of the electric motor and an output powershaft may be substantially in parallel to a main frame, a dead spacebelow the body frame can be utilized effectively. The layout of thepower unit is easy. Also, a location of the center of gravity at a lowerposition can be achieved.

In the driving apparatus for an electrically operated two-wheeledvehicle of the present invention where the output power shaft of thepower unit is disposed in a coaxial relationship to a pivot shaft and adriving wheel of a rapping connector is provided on the output powershaft, also variation in tensile force of an endless transmitting membersuch as a chain caused by bounding or rebounding of the driving wheelcan be prevented.

Further, in the driving apparatus for an electrically operatedtwo-wheeled vehicle of the present invention, where the power unit iscarried with the electric motor located forwardly, the electric motorcan be cooled effectively by a driving wind.

FIG. 17 is a side elevational view of a motorcycle to which anotherembodiment of the present invention is applied. FIG. 18 is a plan viewthereof. In FIGS. 17, 18 and 19, a body 301 is made of a constructionalresin and covers a body frame 302 which will be hereinafter described. Apower apparatus 303 is supported substantially at the center of the bodyframe 302. A rear wheel 304 is supported for rotation at a rear end of arear fork 305 which is supported for rocking motion on the body frame302 by way of a pivot shaft 305a. A front wheel 306 is supported forrotation on a front fork 307 which extends obliquely forwardlydownwardly from a front end of the body frame 301. A handle 308 isprovided for steering the front wheel 306. A seat 309 is mountedadjacent to the handle 308. It is to be noted that the rear fork 305 isheld by a rear suspension, not shown, such that it may be positioned ata suitable angle.

The body frame 302 includes, as shown in FIG. 19, a head pipe 311. Leftand right upper pipes 312 extend rearwardly substantially in ahorizontal direction from an upper portion of the head pipe 311 to arear portion of the seat. Left and right down pipes 313 extend obliquelydownwardly from an upper portion of the head pipe 311 and further extendrearwardly at an angle near to a horizontal direction by way of anintermediate bent portion. The left and right down pipes 313 are thenbent to rise upwardly. Cross pipes 314 are connected to substantiallymid-portions of the upper pipes 312 and extend in an upward and downwarddirection between the down pipes 313 and the upper pipes 312. Left andright stay pipes 315 extend between the rising portions of the downpipes 313 and rear ends of the upper pipes 312. Cross pipes 316 extendbetween the stay pipes 315 and the upper pipes. Further, a gusset plate317 for the reinforcement is welded to each of connecting portions ofthe head pipe 311, to the upper pipes 312 and the down pipes 313.

The power apparatus 303 includes an electric motor 320 provided on theupper side while an output power shaft 321 is disposed on the lowerside. A transmission 322 is interposed between the electric motor 320and the output power shaft 321. As shown in FIG. 22, a casing whichcovers the power apparatus 303 includes a pair of left and right casingbodies 323 and 324. A casing cover 325 and a transmission cover 326 arefitted on the left side casing body 323.

A driving shaft 320a of the electric motor 320 is supported for rotationby means of ball bearings 328 and 329 mounted on the left and rightcasing bodies 323 and 324. An end portion of the driving shaft 320aextends through the left side casing body 323 into a transmissionchamber 330. A rotor magnet 331 is mounted on an outer periphery of thedriving shaft 320a. Stator coils 332 are disposed outwardly of the rotormagnet 331 and supported on the right side casing body 324. A coolingfan 333 for cooling the electric motor 320 is mounted on the outerperiphery of the driving shaft 320a leftwardly of the rotor magnet 331.Warm air, after cooling which flows outwardly in a diametricaldirection, impelled by the cooling fan 333, flows into the transmissionchamber 330 by way of a hole 334 formed in the left side casing body323.

A drive unit 336, for controlling the electric motor, is mounted on theright side casing body 324 which is positioned on the left side of theelectric motor 320 by means of bolts. The center of the drive unit 336is formed as a hollow portion 336a. The hollow portion 336a is utilizedas a passageway through which a cooling water is admitted into thecasing when the cooling fan 333 is driven.

The transmission 322, which makes use of known V belt, is connected tothe driving shaft 320a of the electric motor. A transmission outputpower shaft 337, which is an output power shaft of the transmission 322,is transmitted to the output power shaft 321 by way of transmissiongears 338a to 338d and a counter shaft 339.

A first clutch 341 is provided for the transmission of power from theelectric motor 320 to the output power shaft 321 side in a so-calledforward direction. A second clutch 342 is provided for the transmissionof power reversely from the output power shaft 321 to the electric motor320 side. Both the first clutch 341 and the second clutch 342 areprovided on the transmission output power shaft 337. In particular, thefirst clutch 341 effects transmission of power to the output power shaft321 side only when rotation of a driven pulley 343 and so forth exceedsa predetermined rotational speed, for example, 1,200 rpm. On thecontrary, the second clutch 342 effects transmission of power whenrotation of the transmission output power shaft 337 exceeds anotherrotational speed, for example, 700 rpm. The second clutch 342 isprovided mainly to apply engine brake.

As shown in FIG. 21, a passageway 345 for the discharging of a coolingair which extends in the casing from the front side of the body to therear of the body is formed between the left side casing body 323 and thetransmission casing. The passageway 345 is communicated with thetransmission chamber 330 by way of a hole 346 formed in the left sidecasing body 323. Further, baffle plates 345a are formed to extend from aperipheral wall of the passageway 345 so that mud or rainwater may notbe admitted in through the passageway 345.

As illustrated in FIG. 19, forwardly of the power apparatus 303, twoupwardly and downwardly separated batteries 350 and 351 are disposed andsupported on the body frame 302. In particular, the upper side battery350 is mounted by way of brackets 353, 353 on horizontal cross pipes 352which extend between the down pipes 313 and the cross pipes 314. Thelower battery 351 is mounted by way of brackets 355 and 356 on a crosspipe 354 extending between the left and right down pipes 313, 313 andthe cross pipes 314. The two batteries 350 and 351 are set such thatthey may present a rectangular profile as viewed in plan such that thedimension in a leftward and rightward direction may be greater than thedimension in a forward and rearward direction. Attention is paid so thatthe power apparatus 303 at the rear location may be exposed to a drivingair as much as possible.

In FIG. 17, a cover 360 is provided which is constructed of a resinmaterial. A lower end of the cover 360 is hinge coupled so that it maybe opened and closed. In a normal case, an upper end of the cover 360 isarrested by arresting portions or the like 361 making use of resiliencyof the resin so that the cover 360 is held in a closed condition.

With the motorcycle of the construction described above, due to the factthat the electric motor 320 is located on the upper side of the outputpower shaft 321 or the transmission 322 and is thus located at aposition spaced from the ground and that the lower side of the electricmotor 320 is naturally covered with the output power shaft 321 and thetransmission 322, dust, water or the like is not likely to be admitteddirectly into the electric motor from the ground. Further, the electricmotor 320 disposed at an upper location of the body frame 302 can beremoved or remounted readily only if the drive unit 336 is removed fromside of the body, from the right in FIG. 22. The maintenance of themechanism is highly facilitated.

In addition, Since the cooling fan 333 is accommodated in the electricmotor 320 and the motor 320 itself has a cooling function, even if it isdisposed at a location rearwardly of the batteries 350 and 351 at whichit is not exposed to very much to a driving air, the motor will notsuffer from any trouble in properly functioning.

It is to be noted that, while in the embodiment described above thebatteries have a structure wherein they are heated up at two upper andlower stages. The arrangement is not limited to this and the batteriesmay be provided at one upper side or lower side stage. In this instance,if the upper side battery 350 should be removed, an empty space formedtherein may be utilized as a helmet box or may be utilized as a space inwhich a controller for the electric motor or a charger is to bedisposed.

The electric motor is located on the upper side of the output powershaft and the transmission and located at a position spaced away fromthe ground. The lower side of the electric motor is covered by theoutput power shaft and the transmission. Thus, dust, water or the likeis not liable to be directed into the electric motor.

Further, the electric motor disposed above the body frame can be removedor remounted readily from the side of the body independently of theoutput power shaft and the transmission. Also, improvement in themaintenance of the motor can be achieved.

The electric motor itself has a cooling function. Even if the motor isdisposed at a location rearwardly of the battery where it is not exposedvery much to a driving wind, there is no trouble in functioning. Thus,the degree of freedom in arrangement of the motor is increased.

The invention being thus described, it will be obvious that the same maybe varied in many ways. Such variations are not to be regarded as adeparture from the spirit and scope of the invention, and all suchmodifications as would be obvious to one skilled in the art are intendedto be included within the scope of the following claims.

We claim:
 1. An electrically operated saddle vehicle comprising:avehicle frame; at least one front wheel supported on a front wheelsupporting member mounted adjacent to a front portion of said vehicleframe; at least one rear wheel supported on a rear wheel supportingmember pivotally mounted adjacent to a rear portion of said vehicleframe, the rear wheel supporting member being pivotable relative to thevehicle frame about a pivot shaft between the rear wheel supportingmember and the rear portion of the vehicle frame; an electric motorsupported on said vehicle frame between said front wheel and said rearwheel, the electric motor being mounted forward of the pivot shaft andhaving a driving shaft with a longitudinal axis; and transmission meansoperatively connected to said electric motor and at least one of saidfront and rear wheels for providing propulsion for said vehicle, thetransmission means being mounted forward of the pivot shaft and having atransmission output power shaft with a longitudinal axis, thelongitudinal axes of the driving shaft and the transmission output powershaft being generally parallel and horizontal, said transmission meansbeing mounted between the electric motor and ground surface forprotecting said electric motor from dust, water and other foreignparticles; wherein air is directed to contact said electric motor whilesaid vehicle is in motion for cooling said electric motor during use. 2.The electrically operated saddle vehicle according to claim 1, whereinthe vehicle frame is a twin-tube frame.
 3. The electrically operatedsaddle vehicle according to claim 1, further including a swing arm, thepivot shaft being positioned on said vehicle frame and the swing armbeing secured to said pivot shaft and said rear wheel.
 4. Theelectrically operated saddle vehicle according to claim 3, wherein saidpivot shaft has a longitudinal axis which is generally parallel to thelongitudinal axis of the transmission output power shaft of saidtransmission means.
 5. The electrically operated saddle vehicleaccording to claim 1, further including a cover for said electric motor,a plurality of air vent holes being formed in said cover for permittingair to be in communication with said electric motor for cooling saidelectric motor.
 6. The electrically operated saddle vehicle according toclaim 1, further including fan means connected to said electric motorfor cooling said electric motor as said electric motor is utilized. 7.The electrically operated saddle vehicle according to claim 6, furthercomprising a casing having a motor chamber and a transmission chamber,the electric motor and the fan means being mounted in the motor chamberand the transmission being mounted in the transmission chamber.
 8. Theelectrically operated saddle vehicle according to claim 7, furthercomprising at least one clutch mounted in the casing outside of thetransmission chamber, a passageway being provided from the transmissionchamber, the fan means supplying cooling media from the motor chamberthrough the transmission chamber to the at least one clutch, the coolingmedia moving through the passageway from the transmission chamber. 9.The electrically operated saddle vehicle according to claim 8, furthercomprising at least one baffle plate provided in the passageway from thetransmission chamber to protect the at least one clutch from foreigndebris.
 10. The electrically operated saddle vehicle according to claim9, wherein the at least one baffle plate includes a plurality of baffleplates spaced throughout the passageway.
 11. The electrically operatedsaddle vehicle according to claim 1, further comprising at least onebattery connected to the electric motor, the at least one battery beingmounted on the vehicle frame between the electric motor and the frontwheel supporting member.
 12. The electrically operated saddle vehicleaccording to claim 11, wherein two batteries are mounted on the vehicleframe, both of the batteries being mounted between the electric motorand the front wheel supporting member and one of the batteries beinglocated above the other of the batteries.
 13. The electrically operatedsaddle vehicle according to claim 12, wherein the one battery locatedabove the other battery is directly above the other battery such thatthe batteries are vertically aligned.
 14. The electrically operatedsaddle vehicle according to claim 1, further including a chainoperatively connected between said transmission means and said rearwheel for imparting rotation thereto.
 15. The electrically operatedsaddle vehicle according to claim 1, wherein the electric motor ismounted directly above the transmission means such that inclination ofthe motor and transmission means is avoided.
 16. The electricallyoperated saddle vehicle according to claim 1, wherein the longitudinalaxis of the driving shaft of the electric motor is directly above thelongitudinal axis of the transmission output power shaft.
 17. Theelectrically operated saddle vehicle according to claim 1, furthercomprising a drive unit for controlling the electric motor, the driveunit being mounted adjacent a side of the electric motor and beingreadily detachable to provide ready access to the electric motor.
 18. Anelectrically operated saddle vehicle comprising:a vehicle frame; atleast one front wheel supported on a front wheel supporting membermounted adjacent to a front portion of said vehicle frame; at least onerear wheel supported on a rear wheel supporting member pivotally mountedadjacent to a rear portion of said vehicle frame, the rear wheelsupporting member being pivotable relative to the vehicle frame about apivot shaft between the rear wheel supporting member and the rearportion of the vehicle frame; an electric motor supported on saidvehicle frame between said front wheel and said rear wheel and forwardof the pivot shaft; transmission means operatively connected to saidelectric motor and at least one of said front and rear wheels forproviding propulsion for said vehicle, the transmission means beingmounted to the vehicle frame forward of the pivot shaft; a box supportedat a front portion of said vehicle frame, said box including a covermounted for opening; and at least one battery mounted on the vehicleframe forwardly of the electric motor and the transmission means, theelectric motor being located directly above the transmission meanswithin the box.
 19. The electrically operated saddle vehicle accordingto claim 18, wherein the vehicle frame includes a series of pipes oneach side of the electric motor, each of the series of pipes comprisesan upper pipe, a down pipe extending obliquely downwardly from a headpipe adjacent a forward end of the upper pipe, cross pipes extendingbetween the upper pipe and the down pipe and a stay pipe, the down pipesgenerally having a C-shape with each of the stay pipes connecting a rearportion of the down pipes with a rear portion of the upper pipe.
 20. Theelectrically operated saddle vehicle according to claim 19, wherein theat least one battery being located forwardly of the cross pipes whilethe electric motor is located rearwardly of the cross pipes.
 21. Theelectrically operated saddle vehicle according to claim 20, wherein atleast two batteries are provided, one of the batteries being locatedabove the other of the batteries.
 22. The electrically operated saddlevehicle according to claim 18, wherein the vehicle frame is a twin-tubeframe.
 23. The electrically operated saddle vehicle according to claim21, wherein one of the batteries is located directly above another oneof the batteries in order to be vertically aligned.
 24. The electricallyoperated saddle vehicle according to claim 18, wherein the electricmotor has a driving shaft with a longitudinal axis and the transmissionmeans has a transmission output power shaft with a longitudinal axis,the longitudinal axes of the driving shaft and the transmission outputpower shaft being generally parallel and horizontal.
 25. Theelectrically operated saddle vehicle according to claim 24, wherein thelongitudinal axis of the driving shaft of the electric motor is directlyabove the longitudinal axis of the transmission output power shaft. 26.The electrically operated saddle vehicle according to claim 18, furthercomprising:fan means connected to said electric motor for cooling saidelectric motor; and a casing having a motor chamber and a transmissionchamber, the electric motor and the fan means being mounted in the motorchamber and the transmission being mounted in the transmission chamber.27. The electrically operated saddle vehicle according to claim 26,further comprising at least one clutch mounted in the casing outside ofthe transmission chamber, a passageway being provided from thetransmission chamber, the fan means supplying cooling media from themotor chamber through the transmission chamber to the at least oneclutch, the cooling media moving through the passageway from thetransmission chamber.
 28. The electrically operated saddle vehicleaccording to claim 27, further comprising at least one baffle plateprovided in the passageway from the transmission chamber to protect theat least one clutch from foreign debris.
 29. The electrically operatedsaddle vehicle according to claim 28, wherein the at least one baffleplate includes a plurality of baffle plates spaced throughout thepassageway.
 30. The electrically operated saddle vehicle according toclaim 18, further comprising a drive unit for controlling the electricmotor, the drive unit being mounted adjacent a side of the electricmotor and being readily detachable to provide ready access to theelectric motor.